Four billion people between the ages of 20 and 80 snore. Between the ages of 30 and 69, there are at least one billion people on suffer from obstructive sleep apnoea (OSA), or intermittent airflow blockage during sleep. In most cases, these disorders go undiagnosed. In Belgium, an estimated 2.65 million people between 18 and 65 are snorers. At least 580,000 of them, the majority men (400,000), suffer from OSA. According to Stijn Verhulst, head of paediatrics at UZA, one in 10 Belgian children snores, which can lead to behavioural disorders.
Snoring is a usually annoying throat sound produced during both the REM and non-REM phases of sleep. There are many physiological causes but in general it comes from an obstruction in the upper airway at the level of the nasal and pharyngeal passages. In most cases, these obstructions are related to a narrowing of the nose, as in the case of swollen sinuses or obstructive mucus during a cold. In addition, the positions of the uvula and epiglottis when sleeping play a significant role. In people with a lot of fat accumulation under the chin, flabby muscles or a sagging palate, uvula or epiglottis, the upper airway can become narrower and thus cause snoring.
"Snoring is typically a phenomenon in mammals," says De Meyer, clinical coordinator of the Unit for Orofacial Dysfunctions at the Oral and Maxillofacial Surgery Department of the Jan Palfijn Hospital in Ghent and scientific collaborator at the UZ Brussel Sleep Clinic/Lung Diseases. "It’s an evolutionary problem. Snoring is suspected to be less common in primates. Through evolution, along with the development of speech, the upper airway has become longer and narrower. Further research is needed here."
Because the average human spends about a third of their existence sleeping and shares their bed with someone in nearly 60% of that sleep, the importance of snoring is grossly underestimated, according to De Meyer.
"The problem with the data on snoring is that there are no objectified figures, and no one has ever bothered to define snoring precisely," she says. "With my PhD, I wanted to at least fill that gap."
To do so, she studied the acoustic aspect of snoring for her PhD, Fundamentals of Snoring: Patho-physiology, Diagnosis and Treatment.
"The world record level of snoring, according to the Guinness Book of Records, is 93 decibels, which is comparable to the sound of a hairdryer. Someone who breathes in and out quietly produces about 25 to 30dB. An average snorer easily goes above 35dB and at values of 55dB there is serious noise pollution, not for the snorer but for the person who shares the bed with them."
Snoring noise is perceived as very annoying due to its chronicity and loudness. As a result, the other person in the bed often turns to sleeping aids or moves to another room, with resulting ill effects on the relationship or on their own health. Given that snoring is essentially a perceptual problem, it was important to show to what extent the observations of the bed partner should be taken into account when defining snoring.
De Meyer questions why snoring is so little diagnosed in primary care.
"We need to start raising awareness enormously towards the sleep partner. The question for the snorer themselves is simple: do you snore and are you tired during the day? If the answer to both of those is yes, then there is a problem."
Snoring, according to De Meyer, is reaching pandemic proportions,
"with enormous consequences for the overall health of snorers and their sleep partners. Internationally, snorers who suffer 15 apnoea events or breathing interruptions per night are exhibiting a problematic form of snoring. In fact, that standard should go down to five apnoea events or fewer. Moreover, most therapies focus on keeping the airways open, which often results in obstructed sleep. My research shows that the use of an oral appliance, a fairly recent technique, is effective in reducing apnoea but needs further investigation in its effect on snoring specifically. In addition, more effort needs to be made to make snoring negotiable and it is best to involve the sleep partner from the outset in solving the snoring problem."